Submarine groundwater discharge as a source of nutrients and trace metals in a Mediterranean bay (Palma Beach, Balearic Islands)
Rodellas, Valentí (Universitat Autònoma de Barcelona. Institut de Ciència i Tecnologia Ambientals)
Garcia-Orellana, Jordi (Universitat Autònoma de Barcelona. Departament de Física)
Tovar Sánchez, Antonio (Institut Mediterrani d'Estudis Avançats)
Basterretxea, Gotzon (Institut Mediterrani d'Estudis Avançats)
López-Garcia, José M. (Instituto Geológico y Minero de España)
Sánchez-Quiles, David (Institut Mediterrani d'Estudis Avançats)
Garcia-Solsona, Ester (Universitat Autònoma de Barcelona. Institut de Ciència i Tecnologia Ambientals)
Masqué Barri, Pere (Universitat Autònoma de Barcelona. Departament de Física)

Date:	2014
Abstract:	Submarine Groundwater Discharge (SGD) from a detrital coastal aquifer into the adjacent marine environment was investigated in a Mediterranean bay (Palma Beach, Balearic Islands). In this region, agriculture and tourism are potential sources of groundwater contamination. A survey in the Palma Beach revealed N, Fe and chlorophyll a enhancement associated to areas of preferential groundwater discharge from the nearby coastal aquifer. Groundwater sampling from wells and coastal piezometers indicated high concentrations of dissolved inorganic nitrogen and Fe (up to 2800μmolL-1 and 8100nmolL-1, respectively). Other nutrients, such as DIP, and trace elements were not particularly elevated, which is attributed to the adsorptive characteristics of the carbonated composition of this detrital aquifer and/or the lack of major sources. Cross-shore gradients of 223,224,226Ra isotopes indicated a diffusive shore-based source of these radionuclides and allowed estimates of a SGD flow of 56,000±13,000m3d-1. Our results show that SGD is a major pathway for delivering DIN (1900mmolm-1d-1), dissolved Fe (4. 1mmolm-1d-1) and, to a lesser extent, DIP (16mmolm-1d-1) into the nearshore waters. This allochthonous input may sustain a substantial phytoplankton biomass resulting in an onshore-offshore gradient (4. 7-7. 1mgm-3 in nearshore seawater as compared with <1mgm-3 in offshore stations). This work emphasizes the relevance of SGD-driven nutrient and trace metal inputs in the regulation of nearshore phytoplankton communities of oligotrophic areas.
Grants:	Ministerio de Ciencia e Innovación CGL2008-00047/BTE Ministerio de Economía y Competitividad CTM2012-39476-C02-01 Ministerio de Ciencia e Innovación AP2008-03044 Ministerio de Educación EX2009-0651
Rights:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, i la comunicació pública de l'obra, sempre que no sigui amb finalitats comercials, i sempre que es reconegui l'autoria de l'obra original. No es permet la creació d'obres derivades.
Language:	Anglès
Document:	Article ; recerca ; Versió acceptada per publicar
Subject:	Submarine Groundwater Discharge (SGD) ; Nitrogen ; Phosphorus ; Iron ; Metals ; Mediterranean ; Radium isotopes
Published in:	Marine Chemistry, Vol. 160 (March 2014) , p. 56-66, ISSN 0304-4203

DOI: 10.1016/j.marchem.2014.01.007

Postprint 44 p, 1.8 MB

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Research literature > UAB research groups literature > Research Centres and Groups (research output) > Experimental sciences > Institut de Ciència i Tecnologia Ambientals (ICTA)
Articles > Research articles
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